This invention relates to the characterization of digital images and, more particularly, to an apparatus and method for extraction of unique image features through use of statistical mathematics. Image characterization systems have long been used to determine unique features of image content, for many purposes, including image registration, image change detection, locating certain objects in images, and detecting hidden information in images. Unfortunately, such systems are slow and computationally-expensive, involving elaborate and complicated mathematical methods acting upon spatially or spectrally-derived image features. Prior art systems have evolved wherein the operator must have significant expertise in image science, and must manually adjust many parameters of the mathematical processes to achieve satisfactory image characterization for purposes such as those described above.
While prior art systems work acceptably well for certain image characterization applications, they suffer from several disadvantages including specialized operator expertise requirements, lack of effective automation, large demands upon processing resources, slow processing speeds, low-accuracy of registration, erroneous or ambiguous change detection, and erroneous or ambiguous object location, and are ineffective in reliably detecting hidden information in images.